There were 11 gang shootings in Los Angeles over this year's Father's Day weekend, a holiday that can be bittersweet for young men alienated from their fathers. Deputy Mayor Guillermo Cespedes, who heads Mayor Antonio Villaraigosa's anti-gang efforts, was so distraught over the carnage that he dragged himself home at the end of the weekend and sat down to write his letter of resignation. He labored over it for an hour or so. Then he put the letter away and went back to work.

Modest, insightful and slightly rumpled, Cespedes is one of Los Angeles' most quietly effective city leaders, despite having what must be one of its least-enviable responsibilities: Day in, day out, he spearheads the effort to reduce gang violence. It's a draining task, with few political rewards and the omnipresent possibility of disaster.

Other city officials — those who work in such areas as transportation or housing or planning — measure their work in time saved, constituents served, projects completed. For Cespedes, it's measured in lives. "My normal," he said after another tough stretch recently, "is not their normal."

The business of addressing gang violence is part research and part experiential; it requires being rigorous about results while being open to improvisation. This year, for instance, one of Cespedes' gang-intervention workers suggested introducing softball into the city's nighttime sports offerings. Why? It's competitive but low contact, and players can talk to each other during lulls in the game. That fosters more collegiality than bitterness.

Anecdotally, the softball games were a successful addition to Cespedes' program — known as GRYD, for Gang Reduction and Youth Development. And there are hard numbers to suggest that the program overall is succeeding. According to a study by the Urban Institute, since GRYD began operating, gang crimes have fallen by 21.6%, faster than crime overall in the city; in the two years before it opened, they dropped 14.9%. Moreover, GRYD is reaching large numbers of at-risk youngsters: Young people enrolled in the program were 29% less likely to skip class, while those from the same neighborhoods not in the program increased the amount they cut class by 53%.

Cespedes is a native of Cuba who speaks in a soft voice with a gentle accent, forming his sentences precisely and deflecting compliments. He's been working in community service for 30 years, starting in New York and working his way west. A decade ago, he launched a gang-prevention program in Baldwin Village and, on the success of that model, came to work for Villaraigosa. Since then, GRYD's Summer Night Lights program has attracted national attention (mayors from across the country dropped in on it a few weeks ago) and has become a centerpiece of the city's efforts.

Last week, Cespedes and I spent an evening at the Lou Costello Jr. Recreation Center in Boyle Heights, squarely between the turf claimed by the 18th Street gang and that dominated by the Varrio Nuevo Estrada. Over the years, the border has been a contested one as the two gangs have sparred over everything from girlfriends to the drug trade. And yet, on this night, the park was teeming with families lined up for chicken nachos and young boys and girls "shuffling," the dance style currently the rage in this part of town.

Miguel Leon, who grew up in the neighborhood, was running things at the park, and he eyed the crowd with pride. When he was a kid, Leon remembers, life consisted of school, study, home, maybe the occasional concert in Belvedere Park. But this program has given the community a nighttime center, an oasis from the gang activity that surrounds and suffuses it. "The symbolism of having something like this," Leon added, nodding beneath his beret, "it's really beautiful."

So it seems. All summer, this park — one of 32 such sites in Los Angeles — has hummed with parents and children, teenagers on skateboards, softball and soccer players. Gang members come and go, but they don't dominate the scene; police drop in regularly. And the biggest conflict of the summer was a shoving match over someone cutting in the food line one night.

GRYD doesn't operate alone. It works closely with various programs, and it has an especially important and delicate relationship with the Los Angeles Police Department. The gang-intervention workers who report to Cespedes are there to steer young people away from gangs and to thwart the retaliatory killings that turn one gang killing into a spree. But they're not there to arrest. That falls to the LAPD, where Chief Charlie Beck is an enthusiastic supporter of Cespedes and his work.

Beck worried that Cespedes was too modest to tout his work. So the chief made sure I understood. "GRYD," he said, "is one of the best things this city has done in the last 10 years."

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